Up close and personal with Nearby

Talk presented at the Android Makers conference
Recording: https://www.youtube.com/watch?v=5kL5MLaRVg0

Transcript

1. Up close & personal with Nearby Hugo Visser @botteaap hugo@littlerobots.nl
2. Demo app bit.ly/nearby-demo
3. What is Nearby? Create features based on proximity Android (Play Services) + iOS https://developers.google.com/nearby/
4. Nearby Messages → Publish & Subscribe Notifications → Contextual notifications Connections → P2P connections
5. Messages
6. Messages Android & iOS Publish & Subscribe Ideally less than 3 KB, max 100 KB
7. Messages Nearby API 111001011 010010101 110011100 abc123 abc123 abc123 abc123 111001011 010010101 110011100
8. Setup Create project → https://console.cloud.google.com/apis/ Enable Nearby Messages API Create API key
9. API key in AndroidManifest.xml <application ..> <meta-data android:name="com.google.android.nearby.messages.API_KEY” android:value="your_api_key" /> </application>
10. Publish a message // Create once and keep a reference val client = Nearby.getMessagesClient(this) val payload = byteArrayOf(...) val message = Message(payload, "my_message_type") client.publish(message).addOnSuccessListener { // yay }.addOnFailureListener({ // exception is ApiException })
11. Receiving messages class MyMessageListener: MessageListener() { override fun onFound(message: Message) { } override fun onLost(message: Message) { } } client.subscribe(MyMessageListener()).addOnSuccessListener { // we're listening }.addOnFailureListener { // oh no! }
12. User consent High battery use Invoke on user action No sensitive information
13. Demo
15. Beacons Bluetooth device broadcasting id + tx power, telemetry Standards: iBeacon, Eddystone Often used for (course) location
16. Nearby + Beacons The beacon id is a token Associate token to message → Proximity Beacon API Google Beacon Platform → Beacon Dashboard
18. Beacon console Set beacon status Manage attachments → associate different projects! Shared infrastructure Proximity Beacon API
19. Nearby + beacons Subscribe to beacon messages only Background scanning (screen on) Distance and signal changes for foreground apps
20. Subscribe to beacon messages client = Nearby.getMessagesClient(this, MessagesOptions.Builder(). setPermissions(NearbyPermissions.BLE).build()) // This requires android.permission.BLUETOOTH and ACCESS_COARSE_LOCATION // Android 6.0 and up requires location to be enabled too! client.subscribe(messageListener, SubscribeOptions.Builder(). setStrategy(Strategy.BLE_ONLY).build()). addOnFailureListener { }
21. Subscribe to beacon messages class MyMessagesListener: MessageListener() { override fun onFound(message: Message) { // May receive non-project messages here (check message.namespace) } override fun onBleSignalChanged(message: Message, signal: BleSignal) { } override fun onDistanceChanged(message: Message, distance: Distance) { } }
22. Background subscription client = Nearby.getMessagesClient(this, MessagesOptions.Builder(). setPermissions(NearbyPermissions.BLE).build()) // You can register up to 5 pending intents val pendingIntent = PendingIntent.getBroadcast(...) client.subscribe(pendingIntent, SubscribeOptions.Builder(). setStrategy(Strategy.BLE_ONLY).build()). addOnFailureListener { }
23. Background subscription class MyReceiver: BroadcastReceiver() { override fun onReceive(context: Context, intent: Intent) { Nearby.getMessagesClient(context).handleIntent(intent, MyMessagesListener()) } }
24. Just beacons, no attachments Use MessageFilter.Builder() to scan for specific beacons iBeacon proximity id w/ optional major and minor ids Eddystone namespace with optional instance Obtain beacon id from a Message using IBeaconId and EddystoneUid
25. Demo
26. Notifications
27. Nearby notifications Show notification on Android devices based on beacons Launch url or deep link to app Proxied, filtered, based on relevance, etc, etc Special type of attachment, set by beacon owners
28. How do you prove you own a beacon? A beacon signal is public... So what if I register a large portion of beacons at a national airport?
31. For beacon owners Always register / claim your beacons Google beacon platform is vendor agnostic Share beacons with developers! Still works with platform beacon scanning
32. For beacon owners (proprietary edition) Use “secure id” feature (rotating id’s w/ lookup) Integrate vendor SDK in apps
33. Connections
34. Connections Connect devices in a P2P fashion Uses Bluetooth & WIFI Topologies: P2P_STAR, P2P_CLUSTER, P2P_POINT_TO_POINT
35. Setup <manifest ...> <uses-permission android:name="android.permission.BLUETOOTH" /> <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" /> <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /> <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" /> <!-- Request at runtime on M and up --> <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /> </manifest>
36. Basic steps Advertise & discover Request connection → supplies auth token Accept connection Send payloads
37. Advertising class MyConnectionCallback: ConnectionLifecycleCallback() { override fun onConnectionResult(endpoint: String, result: ConnectionResolution) { } override fun onDisconnected(endpoint: String) { } override fun onConnectionInitiated(endpoint: String, info: ConnectionInfo) { // Make sure to failures from the resulting task! // Instead of accepting, you can also reject or accept later // ConnectionInfo contains an auth token for OOB use client.acceptConnection(endpoint, MyPayloadCallback()) } }
38. Advertising // Get a connections client client = Nearby.getConnectionsClient(this) // First argument is the name for this device // Empty string generates a name client.startAdvertising("", BuildConfig.APPLICATION_ID, MyConnectionCallback(), AdvertisingOptions(Strategy.P2P_CLUSTER)). addOnFailureListener { }
39. Discovery class MyDiscoveryCallback: EndpointDiscoveryCallback() { override fun onEndpointFound(endpoint: String, info: DiscoveredEndpointInfo) { } override fun onEndpointLost(endpoint: String) { } }
40. Discovery client.startDiscovery(BuildConfig.APPLICATION_ID, MyDiscoveryCallback(), DiscoveryOptions(Strategy.P2P_CLUSTER)). addOnFailureListener { }
41. Connection // First parameter is the device name, or generated if empty client.requestConnection("", endpoint, MyConnectionCallback()). addOnFailureListener { // Use status code from ApiException // to check what went wrong }
42. Transfer data class MyPayloadCallback : PayloadCallback() { override fun onPayloadReceived(endpoint: String, payload: Payload) { // Check payload type and handle the (partial) payload } override fun onPayloadTransferUpdate(endpoint: String, update: PayloadTransferUpdate) { // for Payload.Type.Bytes this is not needed, for other types // reports progress (both incoming and outgoing) } }
43. Disconnect // Disconnect a single endpoint, keep other processes going client.disconnectFromEndpoint(endpoint) client.stopDiscovery() client.stopAdvertising() // Prevents accepting and requesting new connections & disconnects everything client.stopAllEndpoints()
44. Demo
45. ĸ github.com/DanielMartinus/Konfetti
46. Connections Hit or miss due to bluetooth issues? Don’t forget to check for errors Stop discovery / advertising before connecting
47. Conclusion Concise and small API Messages, beacon messages Notifications keep on experimenting and register your beacons :) Connections powerful, but not always reliable
48. Thanks! @botteaap hugo@littlerobots.nl speakerdeck.com/hugovisser